Pressure-sensitive fastening part

ABSTRACT

An adhesive closure part for foaming with upholstery parts of vehicle seats during their production comprising a substrate with a plurality of adhesive elements. A bonding agent produces a bonding with the pertinent foam material. The bonding agent is made of an adhesive that is selected to accommodate when the adhesive closure part is made of either a polyamide or a polyolefin material.

Applicant hereby claims the benefit of International Application No.PCT/EP/02886 filed May 15, 1998, relating to the above-identified U.S.patent application, and is incorporated in its entirety herein.

The invention concerns an adhesive closure part, in particular, for thefoaming of upholstery for vehicle seats during their production, withadhesive elements on one side for linkage with corresponding adhesiveelements of another adhesive closure part, by formation of an adhesiveclosure, and with a linking device on the other side of the adhesiveclosure part for the production of a linkage with the pertinent foammaterial.

Such adhesive closure parts are known from EP 0 612 485, wherein theadhesive closure part is placed in a foaming mold in such a way that thelinking device in the form of loop elements on the backside of theadhesive closure part comes into contact with the pertinent foammaterial, so as to produce a firm linkage with it. The opposite frontside of the adhesive closure part has adhesive elements in the form oflinking hooks, adhesives heads, or the like, which are protected fromthe penetration of foam material, for example, as described in theEuropean document, in that they are surrounded on their entire surfaceby an uncrosslinked thermoplastic. If after the foaming process in themold and the removal of the foamed part, the cover is removed, theadhesive elements are free and can later be joined with adhesiveelements of another adhesive closure part, for example, in the form of aloop strip, with the formation of a common adhesive closure.

In this way, it is possible to affix, for example, upholstery coveringmaterials to the foamed upholstery parts of a vehicle seat or anairplane seat or to join rotating components, for example, in the formof grinding wheels to tool holding fixtures, in conventional grindersand apparatuses. The aforementioned foam material can definitely behighly fluid, as a function of the object to be formed and can haveviscosities which are in the range of water or below. It has becomeevident that when using looping and noose-like material as a fastener oreven when using a nappy cloth or the like, the nooses, which are in factopen, are not completely penetrated by the foam material, but ratherform a kind of barrier for it which inhibits the penetration of the foammaterial. In the subsequent hardening or baking process for the foammaterial, there are voids, that is, gaslike hollow occlusions, whichwork against a firm bonding between the adhesive closure part and thefoam material at the transition sites between the looping material andthe foam. As a result of such a reduced strength of the bonding betweenthe adhesive closure part and foam material, there is a loosening of thebonding with continuous stresses, and the adhesive closure part tearsout of the foam material, which can lead to the lack of usefulness ofthe entire component, for example, in the form of a vehicle seat or agrinding disk holding fixture.

On the basis of this state of the art, the goal of the invention is tofurther improve an adhesive closure part of the type mentioned in thebeginning in such a way that a reliable and very strong bonding betweenthe adhesive closure part and the foam material used can be attained.Such a goal can be attained by an adhesive closure part with thefeatures of Claim 1.

Due to the fact that in accordance with the characterizing section, thebonding agent is made of an adhesive base, applied on the other side ofthe adhesive closure part, a kind of primer layer is formed on theadhesive closure part, and this layer enters into a very strong bondingwith the pertinent foam material and thus guarantees a reliable,hard-to-undo bonding between the adhesive closure part and the laterfoam body.

To a specialist in the field of adhesive closures and foamingtechnology, it is surprising that by the application of the adhesivebase on the adhesive closure part, wherein a very thin layer (<0.1 mm)is formed, one attains a better bonding to the foam material than bymeans of a noose-like fabric, which requires a certain expenditure ofeffort and thus is cost-intensive and in which the loops spatiallypenetrate and push forward far into the foam material. Instead of amechanical hooking of looped or noose-like material with the foam, anadhesion to the foam material is produced by means of the individuallyused adhesive base and the primer layer during its production with heatand pressure, which leads to higher strength values with the desiredbonding.

If the adhesive closure part under discussion is made of a polyamidematerial, then resorcinol, polyurethane, and post-crosslinkable polymersare used as the adhesive base. If the adhesive closure or the adhesiveclosure part is made of polyolefin, then polyurethane, or polymers whichare post-crosslinkable are preferably used as the adhesive or primer.

If in a particularly preferred embodiment, the individual adhesive baseis provided with a ferromagnetic material, then the adhesive closurepart can be placed in the metal foam mold in a detachable way and ispositioned in the placed site within the mold via magnetic forces. Inthis way, the placing of the strip-like adhesive closure part can beattained in the foaming molds in a particularly inexpensive manner.

Below, the adhesive closure part is explained in more detail with theaid of various exemplified embodiments and corresponding productionmethods. The figures show the following, in schematic representation:

FIGS. 1-3 with in each case, an adhesive closure part having variousadhesive bases and the method for the application of those adhesivebases.

The presented adhesive closure part is useful, in particular, forfoaming with upholstery parts of vehicle seats (not shown) during theirproduction. The strip-like adhesive closure part, which can also formflat configurations, has on one side, adhesive elements 10 for joiningwith corresponding adhesive elements of another adhesive closure part(not shown), by the formation of a common adhesive closure. The adhesiveclosure part shown in FIGS. 1-3 is produced by an ordinary method, as isshown for example, by DE 196 46 318.1. On the other side or on theunderside of the adhesive closure part, a bonding agent 12 is providedto produce a bonding with the pertinent foam material. The bonding agent12 consists of an applied adhesive base—that is, of a so-called primerlayer.

“Adhesive bases” is the designation for adhesion-imparting media forpaints or coatings. They are highly fluid and thus can be sprayed orspread. Very thin layers are produced (0.005-0.008 mm). Theiradhesion-imparting effect is based thereby on the chemical reaction oftheir components with one another and with the individual surfaces, forexample, made of metal or plastic and for this reason, the designation“reaction partner” is also common. As a rule, adhesive bases produce avarnishing layer. First coats with an adhesive-imparting effect aregenerally designated as primers. They are also sometimes referred to asreaction primers and are correlated with adhesive bases.

The adhesive closure part itself is made of a polyamide or a polyolefinmaterial. Polyamide is the collective designation for high-molecularcompounds which consist of components (amides) linked by peptide bonds.Common polyamides, such as PA 6 or PA66, can be used as the polyamidematerial. To set up the labeling system for polyamide according to ISOor DIN 16 733 T1, nylon, synonymous to polyamide, is also used as thegeneric designation (original trademark of DuPont for PA66). In theEnglish-speaking area, above all, the structure-based IUPAC nomenclatureis also common, for example, poly(imino-(1-oxohexamethylene)) for PA6and poly(imino(1,6-dioxohexamethylene)iminohexamethylene) for PA 66.Because of their special characteristic, polyamides, which containexclusively aromatic radicals (for example, those from p-phenylenediamine/terephthalic acid), are brought together under the genericdesignation aramide, and they are obtained on the market, for example,under the brandname Nomex. More recent developments in this field areblock copolymers of polyamides with polyethers, which have boththermoplastic as well as elastomer properties.

Polyolefins are the all-embracing designation for polymers of thefollowing general structure:

in which R¹ generally stands for hydrogen and R² for hydrogen, astraight-chain or branched, saturated, aliphatic or a cycloaliphaticgroup. Occasionally, polymers with aromatic groups, for example, thephenyl residue (R²=C₆ H₅, see polystyrene) are also counted among thepolyolefins. Products with R¹=H are also designated as poly(α-olefin)s;they can be considered vinyl polymers.

Polyolefins with great industrial importance in the field of adhesiveclosures are, for example, polyethylenes, polypropylenes, polybutenes,which are also occasionally, erroneously, named polybutylenes orpolybutenes [sic], as well as polyisobutenes andpoly(4-methyl-1-pentene)s. Polymers of the higher α-olefins, forexample, poly(1-hexene), poly(1-octene), or poly(1-octadecene), however,have had only very limited industrial application in this field up tonow. Among the polyolefins are also copolymers of various olefins, forexample, those of ethylene with propylene.

FIG. 1 refers to an adhesive closure part made of polyamide material.The adhesive base used hereby as a primer layer later enters into astrong bonding with the foam during its production by means of pressureand/or heat, via a hydrogen bridge bond and taking into considerationvan der Waals forces. Furthermore, adhesive forces are active. This isunderstood to mean the adhesive effect between a solid interface and asecond phase, which can consist of individual particles, molecules,drops, or powders, or a continuous liquid or solid film. The adhesioncan be caused by electrostatic forces, by van der Waals forces (theybelong to the intermolecular forces) or even by a real chemical bonding(for example, in the case of chemisorption). It is the cause of thesorption, both the adsorption on an interface as well as the absorptionin an interface layer. The adhesive base consists of resorcinol and/orone of its derivatives, which can be applied, for example, fromalcoholic solutions. Resorcinol or (1,3-dihydroxybenzene,1,3-benzenediol) forms large, colorless, sweet-tasting needles and has amelting point between 109-111° [C.] and a boiling point of 280° [C.].Resorcinol is slightly soluble in water, alcohol, for example, in theform of ethanol, ether, and glycerol and not very soluble in chloroformand carbon disulfide. In the present case, it is used as an adhesive forthe polyamide material. An application roller 14, which, removing theresorcinol from a bath 16, applies it uniformly on the underside of thestrip-shaped adhesive closure part, serves as the application device. Inthe embodiment under consideration, 70 g resorcinol in 930 g ethanol areused, wherein the adhesive closure strip is conducted along the roller14 at the rate of 12 m per minute. For the drying process, approximately70° C. prevails in a drying channel 18.

In the embodiment according to FIG. 2, polyurethane or a polyurethanecomposition is used as the adhesive base, wherein, in turn, the adhesiveclosure is made of a polyamide material. Polyurethanes are theall-embracing designation for polymers (polyadducts), with groups of thefollowing type, accessible by polyaddition from two-valent andhigher-valent alcohols and isocyanates:

as characteristic basic components of the base macromolecules. In manycases, polyurethanes are produced as prepolymers with terminalisocyanate groups, which cure with the use of moisture from the ambientair, with chain prolongation and perhaps crosslinking. Such prepolymerscan also have a chain prolongation with diamines, forming polyurethanes,which contain urea groups. NCO-terminated prepolymers play an importantrole in the production of polyurethane dispersions. Depending on theselection and stoichiometric ratio of the starting substances,polyurethanes of very different mechanical characteristics are obtained,which can also be used as more or less hard elastomers in fibrous formor as polyether or polyester urethane rubber, as duroplastic cast resins(also glass fiber-reinforced) and, above all, as foams. In theapplication method presented in FIG. 2, the polyurethane material isapplied to the underside of the adhesive closure part with the adhesionelements 10, via an application nozzle 20. A polyurethane coating methodthus takes place wherein, in turn, the drying process is now carried outin the drying channel at 100° C., and the transporting rate is 6 m/min.700 g SU-9182 from the Stahl Company are used as the coating materialand 300 g Fe of the particle size <10μ, as the ferromagnetic material.With the adhesive closure part produced in this way, it can bedetachably affixed in metal foaming molds, by the magnetic effect of theferro material. “Ferromagnetics” is the designation for such magneticmaterials which exhibit ferromagnetism, wherein the magnetization beginsunder the influence of an external magnetic field. Only at temperaturesbelow the Curie temperature is a substance ferromagnetic, whereinnowadays, elements such as iron, cobalt, nickel, and alloys of thesecomponents (Heusler alloys) are usually counted among theferromagnetics.

The embodiment according to FIG. 3 refers to an adhesive base made ofpolymers, which are formed by means of a post-crosslinking, for example,via irradiation by means of a UV-lamp 22 of curable resins, such asepoxide compounds. The curing via ionizing rays is also designated aslacquer curing. In particular, epoxy resins can be used well as curableresins. In lacquer curing, therefore, the curing of adhesive bases orprimers, applied in the liquid state, is carried out to form surfacelayers. Polymerizable lacquer systems can be cured with ultravioletirradiation or other ionizing irradiation. For UV crosslinking with UWlamps 22, mercury discharge lamps are usually used as light sources,which are suitable, among other things, for acrylic lacquers and certainpolyester lacquers also. Lacquer curing by electron beams (ESH, EBC) canpolymerize monomer-containing lacquers to form hard resistant films. Thepolymerization takes place in fractions of seconds.

In the embodiment under consideration, 873 g of the material sold underthe brandname UVacure 1534 are used as the epoxy resin composition, and97 g tripropylene glycol and 30 g FX-5 12. The application takes placewith a doctor device 24 and the belt speed is 8 m/min for the adhesiveclosure part. The ultraviolet lamp 22 produces 120 W/cm².

If the pertinent adhesive closure part is made of a polyolefin material,then it can be coated with the method in accordance with FIGS. 2 and 3.In this respect, the statements made in the preceding are also valid forsuch a polyolefin closure.

What is claimed is:
 1. An adhesive closure part for foaming withupholstery parts of vehicle seats during their production comprising asubstrate with a plurality of adhesive elements on one side thereof forjoining with corresponding adhesive elements of another adhesive closurepart, with the formation of an adhesive closure and with a bonding agenton the other side of said adhesive closure part for producing a bondingwith the pertinent foam material, wherein the bonding agent is made ofan adhesive base, applied on said other side of the adhesive closurepart and wherein the adhesive closure part is made of a polyolefinmaterial, wherein the adhesive base is polyurethane or a polymer, whichis formed by means of a crosslinking of a curable resin.
 2. The adhesiveclosure part according to claim 1, characterized in that the curableresin is an epoxy resin.
 3. The adhesive closure part according to claim2, characterized in that the adhesive base is applied flat in a thinuniform layer, via a spreading device, a spraying device, or a doctorblade.
 4. The adhesive closure part according to claim 2, characterizedin that the pertinent adhesive base is provided with a ferromagneticmaterial.
 5. The adhesive closure part according to claim 2,characterized in that its adhesive elements consist of individualadhesive heads, which are shaped flat on the head side and haveequivalent heights.
 6. The adhesive closure part according to claim 2,characterized in that it is shaped as a continuous strip or surfacematerial.
 7. An adhesive closure part for foaming with upholstery partsof vehicle seats during their production comprising a substrate with aplurality of adhesive elements on one side thereof for joining withcorresponding adhesive elements of another adhesive closure part, withthe formation of an adhesive closure and with a bonding agent on theother side of said adhesive closure part for producing a bonding withthe pertinent foam material, wherein the bonding agent is made of anadhesive base, applied on said other side of the adhesive closure partand wherein the adhesive closure part is made of a polyamide, whereinthe adhesive base, is made of resorcinol, a derivative of resorcinol, orresorcinol and at least one of its derivatives.
 8. The adhesive closurepart according to claim 7 or 1, characterized in that the adhesive baseis applied flat in a thin uniform layer, via a spreading device, aspraying device, or a doctor blade.
 9. The adhesive closure partaccording to claim 7 or 1, characterized in that the pertinent adhesivebase is provided with a ferromagnetic material.
 10. The adhesive closurepart according to claim 8, characterized in that the pertinent adhesivebase is provided with a ferromagnetic material.
 11. The adhesive closurepart according to claim 7 or 1, characterized in that its adhesiveelements consist of individual adhesive heads, which are shaped flat onthe head side and have equivalent heights.
 12. The adhesive closure partaccording to claim 8, characterized in that its adhesive elementsconsist of individual adhesive heads, which are shaped flat on the headside and have equivalent heights.
 13. The adhesive closure partaccording to claim 9, characterized in that its adhesive elementsconsist of individual adhesive heads, which are shaped flat on the headside and have equivalent heights.
 14. The adhesive closure partaccording to claim 7 or 1, characterized in that it is shaped as acontinuous strip or surface material.
 15. The adhesive closure partaccording to claim 8, characterized in that it is shaped as a continuousstrip or surface material.
 16. The adhesive closure part according toclaim 9, characterized in that it is shaped as a continuous strip orsurface material.
 17. The adhesive closure part according to claim 11,characterized in that it is shaped as a continuous strip or surfacematerial.